System and method for simulating and optimizing surface quality based on the location and orientation of additively manufactured shaped parts

Abstract

To provide a system and method for simulating and optimizing surface quality based on the location and orientation of additively manufactured formed parts.SOLUTION: An additive manufacturing system includes one or more processors configured to determine one or more geometric features of each of a plurality of segments of a molding part at a candidate location of the molding part relative to a platform. The one or more processors are configured to generate a quality score for each of the segments at the candidate location based on the one or more geometric features. The one or more processors are also configured to generate for displaying a simulation model of the molding part at the candidate location. The simulation model includes a graphic indicator corresponding to each of the segments. The graphic indicator represents a quality score for the corresponding segment.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the additive manufacturing of three-dimensional shaped parts.

Background Art

[0002] Additive manufacturing refers to any process for manufacturing three-dimensional shaped parts in which successive layers of a base material are deposited under computer control. The deposited layers are selectively fused by the application of a focused energy source, such as a laser, that heats and bonds the material. The size and shape of the shaped part can be based on a three-dimensional computer model or another electronic data source. Additive manufacturing can be used to manufacture objects with complex structures and shapes. Additive manufacturing techniques for manufacturing metal shaped parts can provide greater design freedom and produce more accurate and reproducible finished products than conventional metal manufacturing techniques, such as die casting and extrusion.

[0003] The setup for an additive manufacturing shaping process includes selecting the design of the shaped part to be built and specifying the placement of the shaped part on the shaping platform of the additive manufacturing equipment. Placement can refer to the location of the shaped part relative to the shaping platform, such as at the center and / or edge of the platform, as well as the planned orientation of the shaped part relative to the platform, such as the rotational and / or angular orientation (e.g., tilt) about the vertical axis of the shaped part. Typically, few, if any, factors are considered when determining the placement of the shaped part relative to the platform. One known consideration is to place multiple shaped parts on the platform to increase the total number of shaped parts that can be printed during a common shaping process.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, the placement of the shaped part is determined without considering how that placement affects the surface and subsurface quality of the resulting shaped part, such as surface roughness, porosity, and other surface quality characteristics. After the additive manufacturing process, the shaped part is typically inspected, and the rough surface of the shaped part is polished to increase smoothness. Post-processing tasks such as polishing the rough surface of the shaped part can be costly, difficult, and time- and / or labor-intensive. Grinding the rough surface and additional post-processing tasks to improve the surface quality of the shaped part reduce manufacturing efficiency and increase manufacturing costs. Further, in the case of parts with inaccessible areas where typical post-processing may not be effective or possible, the current methods may be insufficient. Additionally, if the surface quality, subsurface quality, or dimensional accuracy of the shaped part degrades significantly during the additive manufacturing process, the entire shaped part may need to be discarded, resulting in a waste of time and resources.

Means for Solving the Problems

[0005] In one or more embodiments, an additive manufacturing system is provided that includes one or more processors configured to determine one or more geometric features of each of a plurality of segments of a shaped part at a candidate location of the shaped part relative to a platform. The one or more processors are configured to generate a quality score for each of the segments at the candidate location based on the one or more geometric features. The one or more processors are also configured to generate a simulation model of the shaped part at the candidate location for display. The simulation model includes a graphic indicator corresponding to each of the segments. The graphic indicator represents the quality score of the corresponding segment.

[0006] In one or more embodiments, a method (e.g., a method for simulating the surface quality of an additive manufactured shaped part) is provided. The method includes determining one or more geometric features of each of a plurality of segments of the shaped part at a candidate position of the shaped part relative to a platform. The method also includes determining a quality score for each segment at the candidate position based on the one or more geometric features and generating a simulation model of the shaped part at the candidate position for display. The simulation image includes a graphic indicator corresponding to each of the segments. The graphic indicator represents the quality score of the corresponding segment.

[0007] In one or more embodiments, an additive manufacturing system is provided that includes one or more processors configured to determine one or more geometric features of each of a plurality of segments of a shaped part at a candidate position of the shaped part relative to a platform. The one or more geometric features include an angle of incidence between a beam line extending from an electromagnetic energy source of the additive manufacturing equipment and the surface normal of each skin of the corresponding segment proximate to the beam line. The one or more processors are also configured to determine a quality score for each segment at the candidate position based on the one or more geometric features, and a segment of the shaped part with a smaller angle of incidence has a higher quality score than a segment of the shaped part with a larger angle of incidence. The one or more processors are configured to provide one or more preferred positions of the shaped part to achieve an improvement in the quality of the shaped part by additive manufacturing the shaped part at one of the one or more preferred positions for additive manufacturing of the shaped part by comparing the quality scores of the segments at the candidate position with the determined quality scores of the segments of the shaped part at other candidate positions.

[0008] These and other features, aspects, and advantages of the present disclosure will be better understood by reading the following detailed description with reference to the accompanying drawings, in which like numerals represent like parts throughout the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0010] The foregoing summary, as well as the following detailed description of certain embodiments, will be better understood when read in conjunction with the accompanying drawings. As used herein, an element or step recited in the singular and preceded by the word "a" or "an" should not necessarily be construed as excluding a plurality of elements or steps. Further, reference to "one embodiment" is not intended to be construed as excluding the existence of additional embodiments that incorporate the recited features. Further still, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or elements with a particular characteristic may include additional elements that do not have that characteristic.

[0011] Considering the cost, time, and labor of performing surface treatment after the additive manufacturing process, there are several advantages to technologies for additive manufacturing of shaped parts that essentially improve surface quality, quality near the surface, and geometric accuracy, thereby eliminating or at least facilitating post-shaping surface treatment. Embodiments of the present disclosure provide a system (e.g., an additive manufacturing system) and method for simulating the surface quality of an additive manufactured shaped part. For example, based on input parameters regarding part design and the presented position within the additive manufacturing equipment, the system and method can generate a virtual simulation data model. The virtual simulation model (also referred to herein as the simulation model) is a representation of the shaped part and shows the predicted surface quality of each of the different segments of the shaped part when the shaped part is additively manufactured at the presented position. The simulation model is a prediction generated before the shaped part is additively manufactured. The simulation model can be generated according to mathematical functions and / or past experimental observations. The simulation model can be displayed as one or more images on a display device so that an operator can observe it. The simulation of surface quality enables adjustments to be made before shaping the part based on the presented information. For example, an operator or an automated system can change the presented position of the shaped part on the shaping platform of the additive manufacturing equipment to improve the surface quality of one or more specific surfaces of the shaped part and / or to improve the overall surface quality of the shaped part. The systems disclosed herein enable the construction of shaped parts with a high level of surface quality and dimensional accuracy. For example, the system can generate shaped products that meet quality requirements without post-treatment or with only limited post-treatment to improve surface quality.

[0012] The shaped parts described in this specification refer not only to physical objects generated via an additive manufacturing process but also to virtual objects designed to be additively manufactured. The position or positioning of a shaped part within an additive manufacturing apparatus refers to the location and orientation of the shaped part. For example, the location represents a specific area of the shaping platform of the additive manufacturing apparatus on which the shaped part is built layer by layer. In many cases, since multiple shaped parts are built during a common shaping process, the shaped parts are arranged at different locations along the upper surface of the shaping platform. The orientation of a shaped part generally refers to the direction in which the shaped part (to be built) faces and the inclination or tilt of the shaped part. For example, the shaped part can be oriented about its longitudinal axis. The orientation can include rotation of the shaped part about its longitudinal axis. The orientation can also include the inclination or tilt of the longitudinal axis with respect to a vertical axis.

[0013] The surface quality of a given surface can refer to surface roughness, the porosity content of the walls defining the given surface, the structural and / or compositional uniformity of the walls, etc. Generally, a high-quality surface of an additively manufactured shaped part has fewer pores, smaller pores, and is smoother (e.g., has less roughness) than a low-quality surface. One or more of the embodiments described in this specification are configured to manufacture shaped parts having desirable and / or satisfactory surface and subsurface quality and dimensional accuracy, reducing the scrap rate and the amount of surface finishing during post-processing after the shaping process.

[0014] In one or more embodiments disclosed herein, the system analyzes candidate positions for a specified shaped part on a platform. The candidate positions can be input via an operator or selected by the system. The system can determine one or more geometric features of each of a plurality of different segments or sections of the shaped part based on the geometric shape of the part and the candidate positions. The system can use one or more geometric features of each segment to generate a quality score for its surface. For example, the system utilizes the geometric features determined for a first segment of the shaped part to calculate the quality score for the first segment, and the system utilizes the geometric features determined for a second segment of the shaped part to calculate the quality score for the second segment. The quality score represents the prediction accuracy, surface quality, and / or subsurface quality of the corresponding segment. The surface quality can include the predicted roughness, porosity, etc. of the surface of the segment. The quality score is a prediction or estimation of the quality of the segment of the physical shaped part when the additive manufacturing equipment is controlled to build the shaped part according to the input part design, the placement of the part on the platform, and the shaping parameters (e.g., output, speed, beam diameter, beam path separation, etc.). The system can generate different quality scores for different segments of the shaped part at least partially due to different orientations and locations of the segments with respect to the electromagnetic energy source that emits the focused energy beam for the reasons described herein. One or more embodiments described herein can then simulate the quality of the shaped part to be subsequently built and adjust one or more parameters prior to manufacturing the shaped part to improve the accuracy, surface quality, and / or subsurface quality of the shaped part compared to shaping the part at a random or initially presented position.

[0015] The system generates a simulation model based on quality scores for different segments that are different from the component design. For example, the simulation model can include or represent one or more virtual images of the shaped component according to the component design. The virtual image can be two-dimensional or three-dimensional. The simulation model can also simulate the shaped component at different times during the shaping process to show the construction of different layers. Optionally, the displayed virtual image can include graphic indicators superimposed on segments of the shaped component. For example, the virtual image can superimpose a first graphic indicator on a first segment of the shaped component and a second graphic indicator on a second segment. The graphic indicator can be a color, number, character, symbol, etc. corresponding to the quality score. Since the first graphic indicator represents the first quality score, the system selects the first graphic indicator, and since the second graphic indicator represents the second quality score, the system selects the second graphic indicator. In a non-limiting example, if the first and second quality scores indicate that the first segment is predicted to have a higher surface quality than the second segment, the first graphic indicator can be a color associated with good or high quality, such as green, and the second graphic indicator can be a color associated with bad or low quality, such as orange. By displaying the virtual image on a display screen, the system described herein can provide a visual representation of the predicted surface quality along different segments of the shaped component to a person, such as an operator of an additive manufacturing apparatus, before depositing a layer of powder in the additive manufacturing apparatus to actually construct the shaped component.

[0016] Optionally, the operator can use the input device of the system to input a second candidate position of the shaped part having different locations on the platform and / or a different direction from the previously analyzed candidate positions. The system is configured to repeat the analysis based on the second candidate position and generate a second virtual image of the shaped part. The second virtual image includes a graphic indicator representing a quality score determined based on the geometric features of the segments of the shaped part at the second candidate position. This process can be repeated any number of times to generate a plurality of virtual images indicating the predicted quality characteristics of the shaped part manufactured at different locations and / or directions for the additive manufacturing equipment. The predicted surface quality information presented to the operator can be used to determine a more preferred (e.g., optimized) part position within the build envelope of the additive manufacturing equipment than when the shaped part is randomly placed or placed based only on spacing considerations. When the operator selects a desired position, the system can control the additive manufacturing equipment to build the shaped part layer by layer at the selected position (e.g., location and orientation).

[0017] In one embodiment, the system can automatically evaluate many potential candidate positions of the shaped part (without operator input) to determine a group of one or more preferred positions predicted to have a higher quality than other candidate positions being evaluated. The system can then present the one or more preferred positions to the operator so that the operator can select which preferred position to choose to shape the shaped part.

[0018] FIG. 1 is a schematic diagram of an additive manufacturing system 100 according to an embodiment. The additive manufacturing (AM) system 100 includes an additive manufacturing (AM) apparatus 101, a control unit 108, an input device 134, and a display device 136. The AM apparatus 101 includes a shaping platform (or plate) 102, an enclosure 104, an electromagnetic energy source 106, and a raw material applicator 117. The platform 102 is a flat surface of the AM apparatus 101 and can be represented by a plate, the lower wall of the enclosure 104, etc. The AM apparatus 101 executes an additive manufacturing shaping process to form a three-dimensional shaped part 116. Each shaped part 116 is shaped from the upper surface 110 of the platform 102 by selectively depositing the raw material 111 in successive layers 114 and fusing the raw material 111 at locations specified according to a shaping plan 132. Each layer 114 is relatively thin, for example, 1 mm or less, 0.5 mm or less, 0.25 mm or less, etc.

[0019] The AM system 100 of FIG. 1 can be utilized to perform powder bed fusion additive manufacturing technology. Suitable additive manufacturing processes can include, for example, vat photopolymerization (such as stereolithography, digital light processing, continuous digital light processing, light-emitting diodes, etc.), powder bed fusion (such as binder jetting, selective laser melting, etc.), material jetting (such as material jetting, nanoparticle jetting, drop-on-demand, etc.), and multi-jet fusion. Most, if not all, of these processes involve depositing a layer of material on a shaping surface and fusing selected portions of the material using energy and / or in the form of a polymer binder to scan the surface based on a CAD pattern. Other processes include powder feed or wire feed directed energy deposition (DED), in which a wide layer is not deposited on the shaping surface and the material is only deposited on the shaped part without selectively fusing the layer of material.

[0020] The raw material 111 can be in powder form. In non-limiting examples, the powder includes one or more metals in the form of metal particles, flakes, etc. The powder can optionally also include a non-metallic filler material mixed with the metallic material. The metallic material can include various metal types such as aluminum, stainless steel, copper, nickel, cobalt, titanium, etc., and alloys of various metal types. Possible non-metallic filler materials within the powder can include ceramics, polymers (e.g., plastics), silica, etc. The powder that is deposited but not fused to form part of the fabricated part 116 defines a powder bed 122 of unused material 111 contained within the wall 112 of the enclosure 104. In one embodiment, the part 116 is placed within the powder bed 122 during the fabrication process. In an alternative embodiment, the raw material 111 does not contain metal.

[0021] The fabricated part 116 is gradually formed or constructed by collecting layers 114 in the build direction 124 along the build axis 126. Each time material 111 is continuously added on top of the part 116, the part 116 grows in the build direction 124. The build direction 124 extends away from the platform 102. In the illustrated embodiment, the build axis 126 is orthogonal to the plane of the upper surface 110 of the platform 102.

[0022] The AM system 100 generates a new layer of the part 116 by spreading a thin layer or layers of the powder material 111 on top of the part 116. For example, the raw material applicator 117 of the AM system 100 deposits each layer 114 of the material 111. The raw material applicator 117 includes or represents a spreader or recoater device that evenly spreads a thin layer of the material 111, an injector that injects the material 111, etc. The material 111 can be stored in a reservoir before use. The raw material applicator 117 is controlled by the control unit 108.

[0023] Next, the electromagnetic energy source 106 is controlled by the control unit 108 to emit focused electromagnetic energy towards the raw material 111 of the top layer 114, fusing the designated portion of the material 111 to the shaped part 116 and defining a new layer or portion of the part 116. The focused electromagnetic energy can be in the form of a beam that impinges on the layer of powder, melting the selected portion of the layer and adhering it to the part 116 to form its new upper portion. For example, the energy source 106 can be a laser device that generates a high-energy laser beam. In one embodiment, the electromagnetic energy source 106 is suspended above the upper portion of the powder bed 122. For example, the electromagnetic energy source 106 can be disposed approximately 0.5 meters (m) above the upper surface 110 of the platform 102. The focused electromagnetic energy emitted from the energy source 106 can be directed to different locations of the powder bed 122 to fuse different selected portions of the top layer 114 to the part 116. The electromagnetic energy source 106 can include a scanning head that enables the beam to be directed to different locations within the designated coverage area without moving (e.g., shifting) the location of the electromagnetic energy source 106 relative to other components of the AM apparatus 101. The orientation of the scanning head and the parameters of the energy beam (e.g., timing, energy intensity, beam width, etc.) can be controlled by the control unit 108 via a control signal. This process is continuously repeated according to the instructions within the shaping plan 132 until the shaped part 116 is fully formed.

[0024] The AM machine 101 can be controlled to form one or more external supports 120 during a shaping process to structurally support the overhanging features of the shaped part 116 according to the shaping plan 132. The one or more external supports 120 are formed in a stacked manner during the same shaping process as that for forming the shaped part 116. For example, both the shaped part 116 and the external supports 120 are composed of a series of stacked material layers that are fused together during an additive manufacturing shaping process. Optionally, the internal structure (e.g., density, lattice, etc.) and / or material composition of the external supports 120 may be different from those of the shaped part 116. For example, the structure of the external supports 120 may have a lower density than the structure of the shaped part 116.

[0025] The control unit 108 represents a hardware circuit that includes and / or is connected to one or more processors 118 (e.g., one or more microprocessors, integrated circuits, microcontrollers, field programmable gate arrays, etc.) that perform the operations described in relation to the control unit 108. The one or more processors 118 can operate based on programmed instructions. The one or more processors 118 can include a single processor or multiple processors that operate to perform the functions described herein. The one or more processors 118 are referred to herein in the plural as "processors" without limiting the scope to cases where multiple processors 118 are required. The control unit 108 also includes a tangible non-transitory computer-readable storage medium (e.g., a memory) 130. The memory 130 can store programmed instructions (i.e., software) that direct the operation of the processors 118. For example, the memory 130 stores the shaping plan 132 related to the shaped part 116 being manufactured.

[0026] Memory 130 can also store the component design file 138 of the shaping component 116. The component design file 138 can be a computer-aided design (CAD) file or another data file that describes the physical characteristics of the component 116, such as the shape, size, and / or composition of the component 116. The shaping plan 132 can be generated based on the component design file 138. For example, the shaping plan 132 can be a data file that instructs the parameters, conditions, settings, and / or operations of the AM device 101 to generate a physical shaping component 116 that is a replica or equivalent of the virtual component defined by the design file 138. One or more parameters or settings indicated by the shaping plan 132 can include the placement of the shaping component 116 on the platform 102, a series of actions taken by the AM device 101 to shape the component 116 (e.g., the path of the focused energy beam), the position of the support 120, etc. Additional parameters specified in the shaping plan 132 can include settings such as focused electromagnetic energy (e.g., power, beam width, etc.), offset, layer thickness, gas flow parameters, etc. The control unit 108 (e.g., its processor 118) controls the operation of the electromagnetic energy source 106, the raw material applicator 117, and / or other components based on the shaping plan 132 to generate the shaping component 116.

[0027] The processor 118 of the control unit 108 is communicably connected to the input device 134 and the display device 136. The input device 134 may include a touch pad, a touch screen, a keyboard, a mouse, physical buttons, a joystick, and the like. The input device 134 enables an operator to give commands to the AM system 100. In a non-limiting example, the operator can use the input device 134 to select and / or change candidate positions of the shaping part 116 on the platform 102. The display device 136 includes a display screen configured to display a simulation image generated by the control unit 108. Optionally, the input device 134 and the display device 136 can be integrated together within a single device such as a laptop computer, a desktop computer, a workstation, a tablet computer, a mobile phone, a handheld computing device (e.g., a smartphone). The processor 118 can be operably connected to the input device 134 and / or the display device 136 via a wired or wireless communication path.

[0028] In one embodiment, the processor 118 of the control unit 108 is configured to generate a shaping plan 132. For example, the processor 118 can access the component design file 138 stored in the memory 130. The processor 118 can receive user input for selecting a desired position of the shaping component 116 on the platform 102. One or more embodiments described herein can assist in selecting the desired position of the shaping component 116. The processor 118 can generate the shaping plan 132 based on the design of the component 116 and the desired position of the component 116. For example, the shaping plan 132 is generated to outline a series of operations of the AM device 101 for shaping the component 116 at the desired location and orientation with respect to the platform 102 as specified by the designated design. The design file 138 of the design can be received from a remote computing device or generated locally via operator input on the input device 134. In an alternative embodiment, the processor 118 does not generate the shaping plan 132, but rather implements control instructions generated remotely from the AM device 101. For example, the machine instructions can be externally processed by a computer or processing unit and transferred to the AM device 101 to be executed by the AM device 101.

[0029] Figure 2 shows a schematic diagram of the AM device 101 according to an embodiment. Figure 2 shows a first coupon 202, a second coupon 204, and a third coupon 206 that are additively manufactured on the upper surface 110 of the platform 102. Coupons 202, 204, 206 are separate and spaced apart from each other, but can represent different segments of a single shaped part such as part 116 shown in Figure 1, which are then joined during the shaping process. The term coupon is used herein in a general non-limiting sense to represent an additively manufactured shaped part and / or structure that is unfinished or finished during the shaping process. In the illustrated embodiment, coupons 202, 204, 206 have the same size, shape, and orientation with respect to the platform 102. Further, coupons 202, 204, 206 are formed using the same material and the same parameters of the energy source 106. Coupons 202, 204, 206 are placed within the powder bed 122. The only difference between coupons 202, 204, 206 is the placement of coupons 202, 204, 206 with respect to the AM device 101 (e.g., the energy source 106 and the platform 102).

[0030] The placement of coupons 202, 204, 206 can represent the location and orientation of coupons 202, 204, 206 with respect to the energy source 106. More specifically, the placement can represent the location and orientation of each of a plurality of different segments or layers of coupons 202, 204, 206 with respect to the energy source 106. The placement can be characterized by the angle of incidence of the individual segments of coupons 202, 204, 206 with respect to the energy source 106, which is also referred to as the angle of incidence to the part surface normal at the laser point.

[0031] The angle of incidence 208 is the angle between the beam line 210 and a line 212 (e.g., its surface normal vector) perpendicular to the skin 214 or side surface of each segment proximate to the intersection of the beam line 210 with the segment. The beam line 210 represents the path of a laser beam or other focused energy beam that is emitted or would be emitted from the energy source 106 to the uppermost or surface layer 216 of each coupon segment to create the surface layer 216. The surface layer 216 is the layer that is most recently formed at a given time and is at the top (e.g., end) of the layer stack. The skin 214 represents the side or edge of one or more layers of each coupon proximate to the beam line 210 and immediately below the surface layer 216. The line or vector 212 is perpendicular to the skin 214. If the skin 214 is curved (e.g., non-planar), the line 212 can be perpendicular to the curved skin 214 at a location immediately below the surface layer 216. Because the shaped part is three-dimensional, the lines 212 of different skin segments of the same or different parts can have different vertical, lateral, and / or longitudinal or depth components relative to the energy source 106. The angle of incidence 208 described herein is based on the placement (e.g., location and orientation) of a given segment of the shaped part relative to the energy source 106. For example, the surface normal 212 is affected by the orientation of the skin 214, and the beam line 210 is affected by the location of the segment (e.g., the skin 214) relative to the energy source 106.

[0032] The three coupons 202, 204, 206 of FIG. 2 have the same size, shape, and orientation with respect to the platform 102. The first coupon 202, the second coupon 204, and the third coupon 206 are, in the illustrated embodiment, overhanging objects. Each of the coupons 202, 204, 206 includes a respective downskin 218 generally facing the platform 102 and an upskin 220 on the opposite side of the downskin 218. The upskin 220 generally faces upward away from the platform 102. Since the downskin 218 and the upskin 220 of each coupon 202, 204, 206 represent angled skins 214, the normal 212 is perpendicular to the regions or portions of the downskin 218 and the upskin 220 proximate to the surface layer 216.

[0033] The three coupons 202, 204, 206 have different positions with respect to the energy source 106, and these are indicated by different incident angles 208. For example, the first coupon 202 defines a first incident angle 208A between a line 212A perpendicular to each downskin 218 and a first beam line 210A. The first coupon 202 defines a second incident angle 208B between a line 212B perpendicular to each upskin 220 and a second beam line 210B. The second coupon 204 defines a third incident angle 208C between a line 212C perpendicular to each downskin 218 and a third beam line 210C. The second coupon 204 defines a fourth incident angle 208D between a line 212D perpendicular to each upskin 220 and a fourth beam line 210D. The third coupon 206 defines a fifth incident angle 208E between a line 212E perpendicular to each downskin 218 and a fifth beam line 210E. The third coupon 206 defines a sixth incident angle 208F between a line 212F perpendicular to each upskin 220 and a sixth beam line 210F. In the illustrated embodiment, the first incident angle 208A, the third incident angle 208C, and the sixth incident angle 208F are obtuse angles (e.g., greater than 90 degrees). The skin 214 associated with the obtuse incident angle is herein referred to as the outskin for the reasons shown below. The second incident angle 208B and the fifth incident angle 208E are acute angles (e.g., less than 90 degrees). The skin 214 associated with the acute incident angle is herein referred to as the inskin. The fourth incident angle 208D is a right angle (e.g., 90 degrees). The skin 214 associated with the right incident angle represents an inflection point or transition point between the outskin and the inskin.

[0034] The orientations of the skins 214 of coupons 202, 204, 206 with respect to platform 102 represent other geometric features that can optionally be used to simulate and predict the quality of the components prior to the shaping process. The orientation of each skin 214 with respect to platform 102 can refer to the inclination angle defined between the surface normal of skin 214 and the upper surface 110 of platform 102 on which coupons 202, 204, 206 are constructed. Generally, the surface normal of the down skin 218 is downward toward the platform, and the surface normal of the up skin 220 is upward away from the platform. The down skins 218 of the first coupon 202, the second coupon 204, and the third coupon 206 all have the same orientation with respect to the platform 102 of FIG. 2, and the up skins 220 of coupons 202, 204, 206 also have the same orientation with respect to platform 102.

[0035] The experimental tests demonstrated that the incident angle 208 between the beam line 210 and the line 212 perpendicular to the skin 214 can significantly affect the formation of shaped parts such as surface quality, quality near the surface, porosity, and dimensional accuracy. For example, in an experimental setup similar to that shown in FIG. 2, the out-skin with an incident angle 208 greater than the specified threshold angle has significantly worse characteristics (e.g., surface and near-surface quality, porosity, and dimensional accuracy) than the in-skin with an incident angle 208 less than the specified threshold angle, although all test parameters were the same. The specified threshold angle can be an angle defined between 70 degrees and 110 degrees, such as 70 degrees, 80 degrees, 90 degrees, 100 degrees, etc. More specifically, the threshold angle can be an angle between 80 degrees and 100 degrees. In a non-limiting embodiment, the specified threshold angle is 90 degrees. When the specified threshold angle is 90 degrees, an incident angle with an obtuse angle is classified as the out-skin, and an incident angle with an acute angle is classified as the in-skin. The out-skin shown in FIG. 2 includes the down-skin 218 of the first coupon 202, the down-skin 218 of the second coupon 204, and the up-skin 220 of the third coupon 206. The in-skin shown in FIG. 2 includes the up-skin 220 of the first coupon 202 and the down-skin 218 of the third coupon 206. These results indicate that some of the down-skin surfaces 218 can be the in-skin (e.g., the down-skin 218 of the third coupon 206), and other down-skin surfaces 218 can be the out-skin with deteriorated characteristics compared to the in-skin (e.g., the down-skin 218 of the first coupon 202 and the second coupon 204). Similarly, some of the up-skin surfaces 220 can be the in-skin (e.g., the up-skin 220 of the first coupon 202), and other up-skin surfaces 220 can be the out-skin (e.g., the up-skin 220 of the third coupon 206).

[0036] A potential explanation for this phenomenon is the different local absorption of focused beam energy due to different angles of incidence of the laser beam with respect to the shape of the proximal part, as suggested in "Position Dependency of Surface Roughness in Parts from Laser Beam Melting Systems" by S. Kleszczynski, A. Ladewig, K. Friedberger, J. zur Jacobsmuhlen, D. Merhof, and G. Witt, which is hereby incorporated by reference in its entirety, Proceedings of the 26th International Solid Freeform Fabrication (SFF) Symposium, 2015, USA, pages 360 - 370. For example, when forming the surface layer 216 along or in proximity to the outer skin surface (e.g., defining an angle of incidence 208 greater than 90 degrees), a portion of the energy of the focused beam can be absorbed by the powder beneath in the powder bed 122, affecting the melt pool.

[0037] Figure 3 shows a close-up of the first coupon 202 shown in Figure 2. The laser beam 226 impinges on the surface layer 216 adjacent to the downskin 218 of the coupon 202. As shown in Figure 2, since the angle of incidence 208A between the laser beam 226 and the line 212A perpendicular to the downskin 218 is greater than 90 degrees, the downskin 218 is classified as an outskin. The high-energy laser beam 226 melts the raw material, resulting in a melt pool 228. The shape of the melt pool 228 may not exactly conform to the dimensions of the part, at least along the region adjacent to the outskin. For example, since the melt pool 228 in Figure 3 penetrates a depth 231 that extends beyond the desired downskin edge 232 of the coupon 202, the energy of the beam 226 blows out into the powder bed 122. The energy absorbed by the powder can form additional undesirable material, herein called a melt expansion 230, along the downskin surface 218 as the material cools and solidifies. The melt expansion 230 can increase the surface roughness (e.g., decrease the surface quality) and increase the porosity and dimensional inaccuracy. Dimensional inaccuracy refers to an increase in the thickness or width of the downskin 218 compared to the thickness / width defined by the desired downskin edge 232. Note that the one or more top layers, including the surface layer 216, can be dimensionally accurate, at least at the current point during the shaping process. As the laser penetrates, the previously formed layers below the one or more top layers grow. In Figure 3, for example, the melt pool 228 grows the melt expansion 230 along a layer 234 that is two layers below the surface layer 216. The melt expansion 230 agglomerates during the additive manufacturing process as additional material layers are formed.

[0038] Continuing to refer to FIG. 2, the angle of incidence 208B in the upskin 220 of the first coupon 202 is quite different from the angle of incidence 208A in the downskin 218 of the first coupon 202. The angle of incidence 208B is an acute angle, indicating that the upskin 220 of the first coupon 202 represents an inskin. The inskin may be related to an improvement in quality characteristics such as surface quality, quality near the surface, porosity, and dimensional accuracy compared to the outskin. The quality variation may be due to the shape of the shaped part underlying the newly deposited surface layer 216. For example, the energy from the laser beam 236 directed along the beam line 210B shown in FIG. 2 may be absorbed by the partially solidified underlying material of the first coupon 202, resulting in less energy being directed towards the powder bed 122 across the boundary of the upskin 220 (compared to the downskin 218). The melt pool 238 formed by the laser beam 236 cannot penetrate the boundary of the upskin 220 due to the angle of the beam 236 with respect to the shape of the coupon 202. For example, the melt pool 238 extends at least partially inwardly towards the lateral center of the coupon 202. In essence, the partially solidified underlying material of the coupon 202 is more present to absorb the energy of the beam 236 than to absorb the energy of the beam 226. As a result, since the heating of the powder bed 122 along the upskin 220 is less than the heating of the powder bed 122 along the downskin 218, the melt expansion and other non-uniformities formed along the upskin surface 220 are reduced, and the surface quality, quality near the surface, dimensional accuracy, and porosity with respect to the downskin 218 are improved.

[0039] As shown in FIG. 2, the incident angle 208D in the upskin 220 of the second coupon 204 is a right angle, which indicates that the beam line 210D is in the same straight line as the angle of the upskin 220 immediately below the layer of the material being deposited or recently volumized. The upskin 220 of the second coupon 204 may be within a conversion zone or a refraction zone between the inskin and the outskin. For example, the refraction zone can represent a range of angles between the inskin and the outskin. The system disclosed herein can process the skin of the refraction zone in a manner different from that of the inskin and the outskin. The refraction zone can be a range centered around an inflection point, such as 90 degrees but not limited thereto. For example, the refraction zone can be between 70 degrees and 110 degrees, between 80 degrees and 100 degrees, etc.

[0040] During an additive manufacturing process in which layers of material are continuously deposited in a stack according to the shape of a specified shaped part, the incident angle of a particular skin of the shaped part with respect to the beam emitter can change over time. For example, FIGS. 4 - 6 show three different stages in the construction of a single coupon 240 over time by an AM device 101 according to one embodiment. The stage shown in FIG. 4 is prior to the stages shown in FIGS. 5 and 6, and the stages are in chronological order as the stage shown in FIG. 5 is prior to the stage shown in FIG. 6. FIGS. 4 - 6 show the appearance of a part being shaped on a platform 102 that gradually descends (e.g., away from the energy source 106) as additional layers of material are deposited. Since the energy source 106 is positioned in the same location in each of the three illustrated stages of the shaping process, the energy source 106 does not move. The coupon 240 representing the shaped part in FIGS. 4 - 6 has a diamond shape with surfaces of parallel and linear upskin 242 and downskin 244.

[0041] The incident angle 246 based on the component shape in the upskin 242 with respect to the energy source 106 changes over time. As described above, the relevant incident angle 246 is defined between the beam line 248 from the energy source 106 and the line 250 perpendicular to the portion of the upskin 242 close to the current surface layer 252 of the coupon 240. In FIG. 4, the incident angle 246 is an obtuse angle (e.g., greater than 90 degrees), which indicates that the upskin 242 has an outskin classification. Segments of the coupon 240 formed at or near the upskin 242 may have reduced quality and / or accuracy and require additional finishing steps after shaping to increase smoothness and / or provide proper dimensional alignment.

[0042] FIG. 5 shows that the platform 102 has moved and an additional portion 254 of the coupon 240 has been formed following the stage shown in FIG. 4. The additional portion 254 extends from the previous surface layer 252 to the current surface layer 256. At the stage shown, the incident angle 246 based on the upskin 242 is a right angle, which indicates that the upskin 242 is at a transition point or inflection point between the outskin classification and the inskin classification. Segments of the coupon 240 formed at or near the upskin 242 of the surface layer 256 are expected to have better quality and / or accuracy than the upskin 242 of the previous surface layer 252 due to the difference in the incident angle 246.

[0043] FIG. 6 shows that the platform 102 has moved further away from the fixed energy source 106 than shown in FIG. 5, and an additional portion 260 of the coupon 240 has been formed following the stage shown in FIG. 5. The additional portion 260 extends from the previous surface layer 256 to the current surface layer 262. At the stage shown, the angle of incidence 246 based on the upskin 242 is an acute angle (e.g., less than 90 degrees), which indicates that the upskin 242 has an in-skin classification. The segment of the coupon 240 formed at or near the upskin 242 of the surface layer 262 is expected to have better quality and / or accuracy than the upskin 242 of the previous surface layers 256, 252 due to the difference in the angle of incidence 246. FIGS. 4-6 show that as the diamond-shaped coupon 240 becomes taller and the position of the surface layer changes with respect to the energy source 106, the upskin 242 can transition from representing an out-skin to representing an in-skin, or vice versa. Thus, evaluate the shape of the multiple layers of the shaped part and the design to determine the effect of the angle of incidence on the shaped part. Optionally, all layers of the shaped part shape along the skin surface are evaluated for classification as either an out-skin, an in-skin, or an inflection point.

[0044] FIG. 7 shows an additive manufacturing apparatus 101 including a virtual shaped part 302 according to an embodiment. The virtual shaped part 302 is disposed at a candidate position 304 on the shaping platform 102. The virtual shaped part 302 represents an internal function of the processor 118 of the control system 108 of the AM system 100 for predicting the surface quality of one or more segments of the shaped part before actually additive manufacturing the shaped part. Optionally, the virtual shaped part 302 shown in FIG. 7 is for illustrative purposes and is not actually displayed to the operator. Alternatively, the virtual shaped part 302 or a similar representation is displayed on the display device 136 (shown in FIG. 1) to indicate to the operator the status of the operation of the processor 118 for predicting part quality.

[0045] The size and shape of the virtual modeling part 302 are based on the part design file 138 (shown in FIG. 1). The processor 118 can access the part design file 138, such as within the memory 130, to determine the design of the modeling part 302. In the illustrated example, the modeling part 302 has a hollow conical shape centered on the central longitudinal axis 308. The design of the modeling part 302 can be based on a coordinate system, such as a spherical / polar coordinate system or a Cartesian coordinate system having three orthogonal axes. For example, all points of the modeling part 302 can have corresponding position coordinates in the coordinate system.

[0046] The candidate position 304 of the shaping part 302 can be selected by the operator using the input device 134 or can be selected by the processor 118 as one of a number of candidate positions to be evaluated. The candidate position 304 refers to the location and orientation of the shaping part 302 relative to the AM device 101, such as the platform 102 and the electromagnetic energy source 106. In FIG. 7, the candidate position 304 is offset from the electromagnetic energy source 106 so that the shaping part 302 is not placed at the center below the energy source 106. The positions of the energy source 106 and the platform 102 can be known by the processor 118. The candidate position 304 can specify a particular separate location on the shaping platform 102 and a particular separate orientation of the shaping part 302 relative to the platform 102. For example, the candidate position 304 can instruct to place the shaping part 302 at the center of the location (x, y, z) on the platform 102 and orient the shaping part 302 such that the longitudinal axis 308 is orthogonal to the upper surface 110 of the platform 102. The orientation can also specify the rotation angle of the shaping part 302 about the longitudinal axis 308 relative to the AM device 101. For example, if the modeled shaping part includes a protrusion, the rotation angle characterizes the orientation of the protrusion about the longitudinal axis 308. The AM device 101 can define a device coordinate system representing the shaping volume. The device coordinate system can be spherical / polar coordinates and / or Cartesian coordinates. The candidate position of the shaping part can be defined in the device coordinate system. In one embodiment, the processor 118 can determine the candidate position 304 by mapping the position coordinates of the shaping part 302 to the device coordinate system. For example, the processor 118 can use a transfer function to convert the position coordinates of the shaping part 302 from the coordinate system of the shaping part to the device coordinate system.

[0047] When a candidate location 304 is determined (e.g., received, accessed, selected, etc.), the processor 118 is configured to determine and analyze the geometric features of the virtual shaped part 302 at the candidate location 304 to simulate the quality of various segments of the shaped part before physically creating the shaped part. The shaped part 302 can be virtually divided (e.g., tessellated) into a plurality of segments. The segments can be of any size and shape. Since each segment has a height as short as the thickness of one layer, the shaped part can be examined layer by layer. Optionally, the height of each segment can represent a plurality of layers of material. In one embodiment, the segment has a dimension of thickness or depth such that the segment contains more material than the visible surface. For example, each segment can have a specified depth such as 0.5 cm, 1.0 cm, etc. Alternatively, the segment may have no dimension of thickness or depth and represent only the surface of the shaped part. In the illustrated embodiment, the segment is a triangle having a height that represents a plurality of layers. For example, the processor 118 determines one or more geometric features of the first segment 312 of the shaped part 302 and the second segment 332 of the shaped part 302. The first segment 312 is shown along the right side of the shaped part 302 in FIG. 7, and the second segment 332 is shown along the left side of the shaped part 302. The first triangular segment 312 is defined by three corners 323, 324, and 325 having known position coordinates. The surface 310 of the first segment 312 is defined between the three corners 323, 324, 325. The surface 336 of the second segment 332 is defined between the three corners 333, 334, 335.

[0048] The geometric features of the segments include the angle of incidence with respect to the electromagnetic energy source 106. For example, the first segment 312 defines an angle of incidence 318 with respect to the energy source 106. The angle of incidence 318 is defined between a beam line 320 extending from the energy source 106 and a line 319 perpendicular to the side surface 310 (e.g., skin) of the segment 312. Since the angle of incidence 318 is greater than a specified threshold value (e.g., 90 degrees), the surface 310 of the first segment 312 is classified as an out-skin surface. The second segment 332 defines an angle of incidence 321 extending with respect to the energy source 106, which is defined between a beam line 326 extending from the energy source 106 and a line 322 perpendicular to the surface 336 (e.g., skin) of the segment 332. Since the angle of incidence 321 is less than a specified threshold value (e.g., 90 degrees), the surface 336 of the second segment 332 is classified as an in-skin surface. The processor 118 can determine the respective angle of incidence of each of the segmented segments of the shaped part.

[0049] The geometric features of the segments optionally also include the angle of each surface with respect to the upper surface 110 of the shaping platform 102, which indicates the inclination of each segment with respect to the horizontal. The angle can be based on the tangent or plane of the surface. The tangent can be determined by the processor 118 based on the position coordinates of points along the surface, such as the coordinates of the corners 323, 324, 325 of the first segment 312.

[0050] In one embodiment, the determined geometric features of the segments (e.g., segments 312 and 332) are used by the processor 118 to predict the quality of the segments when the shaped part is constructed at the candidate location. The quality of the segment can refer to the surface quality, the subsurface quality, and / or the level of accuracy of the segment with respect to the shaping plan. The processor can generate a quality score for each of the segments at the candidate location 304. With respect to the geometric feature of the incident angle, a surface having an incident angle exceeding a specified threshold angle (with respect to the energy source) may have a different quality score than a surface having an incident angle below the specified threshold angle. For example, an incident angle exceeding the specified threshold angle can generally, but not necessarily, be associated with a worse quality than a surface having an incident angle below the specified threshold. Thus, the outer skin surface is expected to have a lower accuracy, surface quality, and / or subsurface quality compared to the inner skin surface. For example, the outer skin surface can be expected to have a higher porosity and / or roughness than the inner skin surface. The quality score assigned to the segment indicates the level of quality predicted for each segment. In a simple embodiment, the quality score can be binary such that the processor 118 can designate segments having an inner skin surface as having good or satisfactory quality and segments having an outer skin surface as having degraded or insufficient quality. In one or more other embodiments, the designation of the quality score can be more dynamic. For example, the processor 118 can distinguish between two different surfaces based on the difference in the incident angle even if both surfaces are classified as inner skin or outer skin. A first segment having a determined incident angle of 40° with respect to the energy source 106 can be scored with a higher quality than a second segment having a determined incident angle of 70°. For example, although the incident angles of both segments are less than 90°, in the first segment with the smaller angle, it is expected that the fluctuations in the melt pool will be reduced (e.g., the risk of forming a melt expansion portion on the surface will be reduced), and it is expected to be of higher quality than the second segment.

[0051] In one embodiment, the processor 118 can input one or more geometric features as variables into one or more functions to determine a quality score. Optionally, the one or more functions can include input variables that may affect surface quality, such as the type of powder or other raw material, output, speed, beam diameter, shaping parameters such as beam path separation, settings such as the direction of the recoater arm moving within the AM device 101, and the direction of the gas flow through the AM device 101. The one or more functions can be based on simulation or predictive data modeling. In one embodiment, the function can be derived from past experimental data that tests the effects of different variables on surface quality. For example, various experiments can be conducted where a number of test coupons are additively manufactured, and the only difference between the test coupons is the position of the test coupon relative to one or more beam emitters of the additive manufacturing device. For example, different coupons in the experiment can have different rotation angles about an axis, different tilt angles relative to the platform, and / or be in different locations on the platform. By observing and recording the surface quality, subsurface quality, and / or geometric accuracy of the resulting various coupons, data associating quality with position can be collected and stored in a database such as a look-up table, mathematical model, etc. Based on this experimental data, one or more functions can be derived.

[0052] The quality score can be the output of one or more functions. As described herein, the surface quality score broadly represents a quantitative or qualitative measure of the predicted part quality when the shaped part is additively manufactured at candidate location 304 according to the simulated shaping parameters and settings. The surface quality score can be a quantitative value within a defined scale, such as a scale from 1 to 10 (where 10 represents the highest surface quality), 1 to 100, etc. Alternatively, the scale can be essentially qualitative, such as including several defined classes. A non-limiting example of a class can be binary, including "satisfactory" for the in-skin surface and "unsatisfactory" for the out-skin surface, as described above. Another example of a qualitative class can include additional classes such as "high quality", "good quality", "sufficient quality", "bad quality", "low quality", etc. The quality score for each segment can include multiple sub-scores, such as different scores for roughness, porosity, geometric accuracy, etc. Based on various reasons (e.g., the intended use of the shaped part), one or more sub-factors may be more important than other sub-factors, so the generation of sub-scores can selectively optimize the higher-weighted sub-factors. After determining the quality score for the segment, the processor 118 can store the quality score in the memory 130 such that the quality score is associated with the candidate location 304. As described above, the segment can represent various shapes and sizes, including individual layers of material deposited on the shaped part. The segment size can be selected such that the in-skin / out-skin transition or change in the surface quality score within an individual segment is below the resolution of the additive manufacturing process.

[0053] The quality score is used to determine the position of the fabricated part to improve the quality of the fabricated part added by the AM device 101 (shown in FIG. 1) as compared to the selection of the position of the fabricated part by another process. In one or more embodiments, the processor 118 can calculate an overall position score associated with the candidate position 304. The overall position score is a metric based on a set of multiple quality scores of different segments of the fabricated part 302 at the candidate position 304. For example, the processor 118 can aggregate the individual quality scores of the segments to calculate the overall position score. In a non-limiting example, the overall position score can be the sum of the individual quality scores, the average of the individual quality scores, or another statistical representation of the set of quality scores associated with the candidate position 304. Optionally, the processor 118 can weight the quality scores of some segments more heavily than other segments. For example, a surface to be machined later is less important than a surface that needs to remain as deposited. Thus, the processor 118 can apply a greater weight to the score of the segment that defines the surface that needs to remain as deposited. The weight can be adjusted by applying a weight modifier to the score. The processor 118 can store the overall position score in the memory 130 or another storage device.

[0054] The processor 118 can be configured to generate a simulation model of the shaped part 302 at the candidate position 304. FIG. 8 shows a simulation model 400 of the shaped part 302 at the candidate position 304 according to one embodiment. The simulation model 400 can be displayed as one or more images of the shaped part 302 with one or more graphic indicators 402 superimposed on different segments of the shaped part 302. The simulation model 400 can be displayed on an output (e.g., display) device 136 to enable an operator of the AM system 100 to visualize the information presented to the simulation model 400. The simulation model 400 can include an indicator 403 representing a general position of an electromagnetic energy source or beam emitter with respect to the shaped part 302. The simulation model 400 includes a first graphic indicator 402A superimposed on the surface 310 of the first segment 312 and a second graphic indicator 402B superimposed on the surface 336 of the second segment 332. The graphic indicator 402 represents (e.g., is based on) the quality score of the segment on which the graphic indicator 402 is disposed. For example, the first graphic indicator 402A on the first segment 312 represents the quality score generated for the first segment 312, and the second graphic indicator 402B on the second segment 332 represents the quality score generated for the second segment 332.

[0055] The graphic indicator 402 displayed on the simulation model 400 can be a color, a number, a character, a word, a shape, a symbol, or the like. In the illustrated embodiment, the graphic indicator 402 is an integer from 1 to 5. The integers represent different quality scores, where 5 represents the class with the highest predicted quality and 1 represents the class with the lowest predicted quality compared to other classes. For example, the first graphic indicator 402A is the number "1", and the second graphic indicator 402B is the number "4", which indicates that at the candidate position 304 of the shaped part 302, the surface 336 of the second segment 332 has a better predicted quality than the surface 310 of the first segment 312. In another embodiment, the graphic indicator 402 can be color-coded such that a high quality score is green and a low quality score is red, etc.

[0056] The simulation model is displayed on the display device 136 for the operator of the AM system 100 to view. The simulation model 400 can be displayed as two-dimensional or three-dimensional. In an example where the displayed simulation model 400 is three-dimensional, the simulation model 400 can be rotatable to display different selected sections of the simulation model 400. For example, the operator can use the input device 134 to rotate the simulation model 400 to view surfaces that were previously hidden. By viewing the simulation model 400, the operator can know the predicted quality of different surfaces of the shaped part 302 at the candidate position 304. For example, the simulation model 400 presents areas predicted to have poor or insufficient surface quality. Based on the information received from the simulation model 400, the operator can determine to adjust the position of the shaped part relative to the AM device for the purpose of improving the quality of the shaped part when deposited. The simulation model can be incorporated into a virtual reality platform and / or an augmented reality platform.

[0057] In response to viewing the simulation image, the operator can use the input device 134 to change the position of the shaping part 302 relative to the platform 102. For example, the operator can input or select a second candidate position. The second candidate position can have a different location on the platform 102, a different rotation direction, and / or a different tilt angle from the (first) candidate position 304. FIG. 9 shows a simulation model 450 of the shaping part 302 at the second candidate position 452 according to one embodiment. The shaping part 302 at the second candidate position 452 is tilted toward the location of the electromagnetic energy source as identified by the indicator 403. For example, unlike the shaping part 302 at the candidate position 304 shown in FIG. 8, the longitudinal axis 308 of the shaping part 302 at the second candidate position 452 is not orthogonal to the upper surface 110 of the platform 102. The simulation model 450 can be generated and displayed on the output device 136.

[0058] In one embodiment, when the second candidate position is determined (e.g., received, selected, calculated, etc.), the processor 118 can repeat the above process to determine a second set of quality scores for various segments of the shaping part 302. The quality score can be determined based on geometric features such as the angle of incidence with respect to the energy source. The processor 118 can determine an overall position score for the shaping part 302 at the second candidate position. The second simulation model 450 can be generated based on the determined quality scores. The simulation model 450 can be displayed simultaneously with or sequentially after the first simulation model 400 so that the operator can compare the two simulation models. The processor 118 can store the details of the second candidate position, the second set of quality scores, the overall position score of the second candidate position, and the second simulation model in the memory 130 and / or another storage device.

[0059] In the system described herein, the placement of the shaped part with respect to the AM device can be manually optimized. For example, based on a comparison between information provided by the first and second simulation models (e.g., the overall position score), the operator can use the input device 134 to select one or more additional candidate positions. For each additional candidate position, the processor 118 is configured to repeat the analysis to generate a new simulation model and / or a new overall position score. The simulation model enables the operator to understand the predicted relationship between the placement of the shaped part 302 and the predicted quality of the segments of the shaped part 302. If the operator has a particular surface area of the shaped part for which a particular threshold level of quality is desired, the operator can adjust the position of the shaped part 302 until the generated simulation model indicates that the predicted quality along that particular surface area meets the threshold. Similarly, the operator can continue to change the candidate position until a candidate position is found, such that the overall position score is greater than the desired score threshold.

[0060] The system described in this specification can provide automated optimization of the placement of the shaping part with respect to the AM device. For example, the processor 118 can generate a recommended position of the shaping part based on the analysis of a plurality of candidate positions without using operator input. The processor 118 can perform an analysis on an initial set of candidate positions to determine a simulation model and / or an overall position score for each candidate position within the initial set. Next, the processor 118 can select one or more preferred candidate positions from the initial set that have better results (e.g., a higher overall position score) than other candidate positions. Optionally, the processor 118 can generate additional candidate positions based on the results of the initial analysis, and at least some of the preferred candidate positions can be generated by the processor 118. The processor 118 can select the best preferred candidate position as the recommended position for use during the actual shaping process. Alternatively, the processor 118 can present the preferred candidate positions, such as the top three candidate positions, to the operator so that the operator can determine which preferred candidate position to select for the shaping process.

[0061] The operator can participate in the automated candidate positioning process. For example, the operator can specify a particular segment of the shaping part that requires higher quality or a particular segment that does not require quality optimization. The operator input can be represented by adjusting the weights associated with various parts of the shaping part. For example, the weight associated with a segment that requires higher quality can be increased, and the weight associated with a segment that does not require quality optimization can be decreased. The operator can also use an input device to specify a desired range of locations / directions. For example, the operator may want to avoid large melting areas (to prevent the accumulation of residual stress in the part) or place a particular surface within a particular location or direction window. The processor 118 can analyze the predicted quality of the shaping part at different candidate positions based on these operator input constraints or parameters.

[0062] In one embodiment, the processor 118 can select a recommended position based on the overall position scores of the analyzed and stored candidate positions. For example, the processor 118 can select, as the recommended position, the candidate position associated with the highest overall position score of the stored overall position scores associated with a particular shaped part 302. In another embodiment, the processor 118 can function as a solver algorithm that essentially "solves" for the position of the shaped part 302 that provides the highest possible surface quality according to the scoring system disclosed herein. For example, the processor 118 can perform a number of calculations by varying different variables to focus on a single candidate position that is predicted to provide an improved surface quality compared to at least some of the other potential positions of the shaped part on the platform. In a non-limiting example, the processor 118 can repeatedly change one variable at a time to establish a large set of different candidate positions and then systematically generate the respective overall position scores for each of the candidate positions within the set. In another non-limiting example, the processor 118 can "smartly" select candidate positions to test based on learned trends, such as the tendency for a surface tilted towards the energy source 301 to be expected to have a better surface quality than a surface tilted away from the energy source 301.

[0063] In the illustrated embodiment, the system predicts that when forming the shaped part at the second candidate position 452, the overall quality of the shaped part will be improved compared to forming the shaped part at the first candidate position 304 shown in FIGS. 7 and 8. For example, the graphic indicators 402 superimposed on different segments of the shaped part 302 within the simulation model 450 have a higher score or number overall than the aggregated graphic indicators 402 of the simulation model 400. Tilting the shaped part 302 towards the energy source is predicted to improve the overall surface quality of the surface by making the surface more uniform across the entire perimeter of the shaped part. For example, when the shaped part 302 is tilted, a portion of the angle of incidence of the line extending from the energy source to the surface of the segment becomes smaller. For example, the graphic indicator 402A on the first segment 312 is "2" in the simulation model 450, which represents an improvement over the "1" shown in the simulation model 400. The increase in the quality score may be due, at least in part, to a decrease in the angle of incidence between the skin or surface 310 of the first segment 312 and the line extending from the energy source. Although the overall quality score may increase, tilting the shaped part may increase the angle of incidence of some segments and may reduce the individual quality scores of those segments. For example, the quality score graphic indicator 402B of the second segment 332 decreases from "4" in the simulation model 400 to "3" in the simulation model 450, which may be based, in part, on the increased angle of incidence.

[0064] Optionally, in addition to or instead of adjusting the orientation of the shaped part 302, different candidate positions may have different locations of the shaped part 302 on the platform 102. For example, the processor 118 can recommend a candidate position that is closer to the energy source than another candidate position. Moving the shaped part closer to the energy source can change the angle of incidence of the energy beam from the energy source that impinges on the shaped part, which may improve the quality of various segments of the shaped part.

[0065] The operator can use the input device 134 to select or confirm the final position of the shaped part 302. The final position can be the preferred position generated by the processor 118, or a position selected by the operator based on the simulation model, the overall position score, and / or other information presented to the operator by the system. Once the position is determined, the processor 118 can generate a shaping plan 132 (shown in FIG. 1) based on the determined position of the shaped part. Next, the AM device 101 can be controlled to additively manufacture a physical shaped part according to the shaping plan 132 such that the shaped part is constructed at a location and orientation that matches the determined position.

[0066] System 100 can also be used to plan the placement of multiple shaped parts that are manufactured simultaneously on the same platform during a single additive manufacturing shaping process. FIG. 10 shows an array 500 of multiple shaped parts arranged at different locations on the shaping platform 102 of the AM device 101 according to one embodiment. The shaped parts include a first part 502 at a first location 503, a second part 504 at a second location 505, a third part 506 at a third location 507, and a fourth part 508 at a fourth location 509. In one embodiment, the locations 503, 505, 507, 509 can be fixed (e.g., set), and the processor 118 can perform a quality analysis for various candidate positions of the shaped parts 502, 504, 506, 508 by modifying the tilt and rotation of the shaped parts 502, 504, 506, 508 to define different candidate positions. Based on the analysis, the processor 118 can determine one or more preferred candidate positions for each of the shaped parts 502, 504, 506, 508. For example, the preferred candidate positions can include the shaped parts 502, 504, 506, 508 that are tilted towards the location of the energy source 106, similar to the tilt of the part 302 shown in FIG. 9.

[0067] The processor 118 can be configured to determine whether any of the shaped parts 502, 504, 506, 508 can meet the minimum quality threshold. The minimum quality threshold can be specified based on standards or usage requirements, or can be selected by operator input. For example, the processor 118 can compare the overall quality scores of the preferred candidate positions of the plurality of shaped parts 502, 504, 506, 508 with the minimum quality threshold. In a non-limiting example, the third shaped part 506 can be the only shaped part within the array 500 that does not meet the minimum quality threshold. For example, none of the candidate positions of the third shaped part 506 result in an overall quality score that meets or exceeds the minimum quality threshold. As a result, the processor 118 can present a notification to the operator that the third shaped part 506 should not be constructed at the set position 507. The notification can be provided via the output device 106 such as a displayed message. Accordingly, the processor 118 can determine other locations for the shaped part 506 on the platform 102 for evaluation, and / or the operator can decide to start the shaping process to shape only the first part 502, the second part 504, and the fourth part 508.

[0068] In another embodiment, the processor 118 can determine the locations of the shaped parts 502, 504, 506, 508 on the platform 102 in addition to the rotation and tilt of the shaped parts 502, 504, 506, 508. For example, the processor 118 can arrange the shaped parts 502, 504, 506, 508 on the platform 102 within the polar array, where the shaped parts 502, 504, 506, 508 surround the energy source 106 and tilt towards the energy source 106.

[0069] FIG. 11 is a flowchart of a method 600 for simulating the surface quality of an additively manufactured shaped part according to an embodiment of the present disclosure. The method 600 is configured to predict the surface quality of various segments of the shaped part before the shaped part is additively manufactured. The predicted surface quality can be used to selectively place the shaped part during the actual additive manufacturing process and compare it with the surface quality achieved at different positions of the shaped part within the manufacturing equipment, thereby improving the surface quality of the manufactured shaped part. The method 600 can be executed in whole or at least in part by one or more processors 118 of the control unit 108 of the AM system 100 shown in FIG. 1. Optionally, some operator inputs can be provided in one or more steps. Optionally, the method 600 can include more steps than those shown in FIG. 11, fewer steps than those shown in FIG. 11, different steps not shown in FIG. 11, and / or steps in a different arrangement or order than those shown in FIG. 11.

[0070] The method 600 begins at 602, where one or more geometric features of each of a plurality of segments of the shaped part at candidate positions of the shaped part relative to the platform are determined. The one or more geometric features include the angle of incidence between a beam line extending from an electromagnetic energy source of the additive manufacturing equipment and the surface normal of the respective skin of the corresponding segment proximate to the beam line.

[0071] At 604, the quality score for each segment of the shaped part at the candidate position is determined based on one or more geometric features. A segment of the shaped part with a small incident angle may have a higher quality score than a segment of the shaped part with a large incident angle. At 606, a simulation model of the shaped part at the candidate position is generated. The simulation image includes graphic indicators corresponding to each of the segments. The graphic indicator represents the quality score of the corresponding segment. At 608, the simulation model is displayed on a display device for an operator to view. At 610, the quality scores of the segments of the shaped part at the candidate position are aggregated, and an overall position score for the candidate position is calculated.

[0072] At 612, the previous steps (e.g., 602, 604, 606, 608, and 610) are repeated at least once at another candidate position of the shaped part for the platform. After multiple cycles, the method may have data including segment quality scores, simulation models, and overall position scores for multiple candidate positions of the shaped part. At 614, at least one preferred position of the shaped part for the platform is determined based on the data at different candidate positions. The preferred position can be determined to improve the quality of the shaped part compared to adding the shaped part at an unfavorable candidate position such as an initial candidate position. At 616, the additive manufacturing equipment is controlled to additively manufacture the shaped part at one of the preferred positions on the platform. The shaped part may automatically select a preferred position at which the shaped part is additively manufactured based on an overall quality score or another metric. Alternatively, an operator can select a preferred position at which the shaped part is additively manufactured from a plurality of preferred positions presented to the operator as options.

[0073] One or more embodiments described herein use information regarding the shape of a shaped part and the location of the shaped part within the shaping envelope of an additive manufacturing apparatus to predict the surface quality of various segments of the shaped part before actually forming a physical shaped part. For example, embodiments described herein can simulate part surface roughness for use in selecting an optimal or preferred part orientation and location within a machine shaping envelope. The generated simulation data can be used with placement optimization algorithms or solver algorithms to provide a recommended location of the shaped part within the machine shaping envelope.

[0074] Various spatial and directional terms such as up, down, lower, center, lateral, horizontal, vertical, front, etc. are used to describe embodiments of the present disclosure, but it is understood that such terms are used only with respect to the directions shown in the drawings. The orientation can be reversed, rotated, or otherwise changed so that up becomes down, or vice versa, or horizontal becomes vertical.

[0075] The figures of the embodiments of this specification show one or more control units or processing units, such as control unit 108 shown in FIG. 1. It should be understood that the control unit or processing unit represents a circuit, circuit configuration, or portions thereof implemented as hardware with associated instructions (e.g., software stored on a tangible non-transitory computer-readable storage medium such as a computer hard drive, ROM, RAM) for performing the operations described herein. The hardware can include a state machine circuit configuration wired to perform the functions described herein. The hardware can include and / or be connected to electronic circuits including one or more logic-based devices such as microprocessors, processors, controllers, etc. Optionally, control unit 108, or one or more of its processors 118, represents one or more such processing circuit configurations such as a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), one or more microprocessors, a quantum computing device, etc. The circuits of various embodiments are configured to execute one or more algorithms to perform the functions described herein. The one or more algorithms include aspects of the embodiments disclosed herein, whether explicitly identified in a flowchart or method or not.

[0076] As used herein, terms such as "control unit" include any processor-based or microprocessor-based system, including a microcontroller, a reduced instruction set computer (RISC), an application specific integrated circuit (ASIC), a logic circuit, and other circuits or processors capable of performing the functions described herein using hardware, software, or a combination thereof. These are merely examples and are in no way intended to limit the definition and / or meaning of such terms. The control unit 108 shown in FIG. 1 is configured to execute a set of instructions stored in one or more storage elements (such as one or more memories) to process data. The set of instructions includes various commands that direct the control unit 108 (e.g., one or more of its processors 118) as a processor to perform specific operations such as the methods and processes of various embodiments of the subject matter described herein. In one embodiment, the set of instructions is in the form of a software program. The processing of input data by the processor is performed in response to user commands, results of previous processing, or requests from another processor. As used herein, the term "software" includes any computer program stored in memory for execution by a computer, including but not limited to RAM memory, ROM memory, EPROM memory, EEPROM memory, and non-volatile RAM (NVRAM) memory.

[0077] As used herein, a structure, limitation, or element that is "configured" to perform a task or operation is specifically structured, constructed, or adapted in a manner corresponding to the task or operation. For clarity and to avoid misunderstanding, an object that can merely be modified to perform a task or operation is not "configured" to perform the task or operation as used herein.

[0078] It should be understood that the above description is intended to be illustrative and not limiting. For example, the above embodiments (and / or aspects thereof) can be used in combination with each other. Further, many modifications can be made to adapt a particular situation or material without departing from the scope of the teachings of the various embodiments of the present disclosure. The dimensions and types of materials described herein are intended to define parameters of the various embodiments of the present disclosure, but the embodiments are in no way limiting and are exemplary embodiments. Upon consideration of the above description, many other embodiments will be apparent to those of ordinary skill in the art. Accordingly, the scope of the various embodiments of the present disclosure should be determined with reference to the appended claims and the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein". Further, terms such as "first", "second", and "third" are used merely as labels and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted under 35 U.S.C. § 112, ¶ 6, unless the phrase "means for" is expressly used in a claim limitation where a further structureless function statement follows.

[0079] This written description discloses various embodiments of the disclosure, including the best mode, using examples. It enables one of ordinary skill in the art to practice the various embodiments of the disclosure, including making and using any device or system and performing any incorporated method. The patentable scope of the various embodiments of the present disclosure is defined by the claims and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements that differ only insubstantially from the literal language of the claims.

Description of Symbols

[0080] 100 Additive manufacturing system 101 Additive manufacturing equipment 102 Shaping platform 104 Enclosure 106 Energy source 108 Control unit 110 Upper surface 111 Material 112 Wall 114 Layer 116 Shaped part 117 Raw material applicator 118 Processor 120 Support 122 Powder bed 124 Shaping direction 126 Shaping axis 130 Memory 132 Shaping plan 134 Input device 136 Output (display) device 138 Design file 202, 204, 206 Coupon 208 Incident angle 208A~208F Incident angle 210 Beam line 210A~20F Beam line 212 Normal, vector 212A~212F Line 214 Skin 216 Surface layer 218 Down skin 220 Up skin 226 Laser beam 228 Melt pool 230 Melt expansion part 231 Depth 232 Down skin edge 234 Layer 236 Laser beam 238 Melt pool 240 Coupon 242 Upskin 244 Downskin 246 Incident angle 248 Beam line 250 Line 252 Surface layer 254 Additional part 256 Surface layer 260 Additional part 262 Surface layer 301 Energy source 302 Shaping part 304 Candidate position 308 Longitudinal axis 310 Side surface, surface 312 Segment 318 Incident angle 319 Line 320 Beam line 321 Incident angle 322 Line 323 - 325 Angle 326 Beam line 332 Segment 333 - 336 Angle 336 Surface 400 Simulation model 402 Graphic indicator 402A, 402B Graphic indicator 403 Indicator 450 Simulation model 452 Candidate position 500 Array 502 Shaping part 503 First position 504 Shaping part 505 Second position 506 Shaping part 507 Third position, setting position 508 Shaping part 509 Fourth position 600 Method

Claims

1. An additive manufacturing system (100), comprising one or more processors (118) configured to determine one or more geometric features of each of a plurality of segments (312, 332) of the build part (302) at a candidate location (304) of the build part relative to a platform (102), the one or more geometric features including an incident angle (318) between a beam line (320) extending from an electromagnetic energy source (106) of an additive manufacturing apparatus (101) and a surface normal (319) of a respective skin (310) of the segment (312, 332) proximate to the beam line, the electromagnetic energy source being configured to emit electromagnetic energy beams in various directions along a plurality of beam lines at a single location of the electromagnetic energy source relative to the additive manufacturing apparatus and the build part to melt a designated portion of the build part, the plurality of beam lines being used to determine the incident angle of the segment, wherein the one or more processors are configured to generate a respective quality score of the segment at the candidate location based on the one or more geometric features. An additive manufacturing system (100).

2. The additive manufacturing system (100) of claim 1, further comprising a display device (136) operably connected to the one or more processors (118), the display device being configured to display a graphic indicator (402) corresponding to each of the segments, the graphic indicator representing the quality score of the corresponding segment.

3. The additive manufacturing system (100) of claim 2, wherein the graphic indicator (402) includes one or more of color, number, or symbol. **Claim 4**: The one or more processors (118) are configured to generate, for display, a simulation model (400) of the shaped part at the candidate position, the simulation model including a graphic indicator (402) corresponding to each of the segments, the graphic indicator representing the quality score of the corresponding segment, the additive manufacturing system (100) according to claim 1. **Claim 5** The one or more processors (118) are configured to determine one or more preferred positions of the shaped part (302) relative to the platform (102) to achieve an improvement in the quality of the shaped part regarding additive manufacturing of the shaped part at the candidate position (304), the additive manufacturing system (100) according to any one of claims 1 to 4. **Claim 6**: The one or more processors (118) are configured to determine the one or more preferred positions of the shaped part (302) based on which positions of the shaped part result in a significant decrease in the angle of incidence of the segment compared to the angle of incidence of the segment at the candidate position (304), the additive manufacturing system (100) according to claim 5. **Claim 7** At the one or more preferred positions of the shaped part (302), the longitudinal axis (308) of the shaped part is inclined towards the electromagnetic energy source (106) of the additive manufacturing apparatus (101), the additive manufacturing system (100) according to claim 5 or 6. **Claim 8** In response to receiving a selection of one of the one or more preferred positions as the determined position of the shaped part (302) relative to the platform (102), the one or more processors (118) are configured to control the additive manufacturing apparatus (101) to build the shaped part at the determined position of the platform by sequentially depositing materials in layers, the additive manufacturing system (100) according to any one of claims 5 to 7. **Claim 9** The one or more processors (118) are further configured to aggregate the quality scores of the segments (312, 332) to calculate an overall position score associated with the candidate position (304), the additive manufacturing system (100) according to any one of claims 1 to 8.

10. The candidate position (304) is a first candidate position, and the one or more processors (118) are based on the one or more geometric features of the segment at a second candidate position (452), the plurality of different segments (312, 332) of the shaped part at the second candidate position of the shaped part on the platform (102) are further configured to generate quality scores, the shaped part at the second candidate position has at least one of a different location, inclination, or rotational orientation relative to the shaped part at the first candidate position, the one or more processors (118) aggregate the quality scores of the segments to calculate an overall position score associated with the second candidate position, and are configured to rank the first and second candidate positions based on the overall position scores of the first and second candidate positions, the additive manufacturing system (100) according to claim 9.

11. The additive manufacturing system (100) according to any one of claims 1 to 10 further includes an input device (134) operably connected to the one or more processors (118), and the one or more processors are configured to receive the candidate position (304) of the shaped part on the platform (102) in response to an operator command provided using the input device.

12. The electromagnetic energy source includes a scanning head configured to direct the electromagnetic energy beam in various directions along the plurality of beam lines without moving the electromagnetic energy source relative to the additive manufacturing equipment or the shaped part, the additive manufacturing system (100) according to any one of claims 1 to 11.

13. A method (600) comprising: Determining, for each one or more geometric features of a plurality of segments (312, 332) of the shaped part at a candidate position (304) of the shaped part with respect to a platform (102), the one or more geometric features including an incident angle (318) between a beam line (320) extending from an electromagnetic energy source (106) of an additive manufacturing apparatus (101) and a surface normal (319) of a respective skin (310) of the segment (312, 332) proximate to the beam line, the electromagnetic energy source being configured to emit electromagnetic energy beams in various directions along a plurality of beam lines at a single location of the electromagnetic energy source with respect to the additive manufacturing apparatus and the shaped part to melt a designated portion of the shaped part, the plurality of beam lines being used to determine the incident angle of the segment; Determining a respective quality score of the segments at the candidate position based on the one or more geometric features. A method (600) comprising the steps. **Claim 14**: The method (600) according to claim 13, further comprising displaying, on a display device (136), a graphic indicator (402) corresponding to each of the segments, the graphic indicator representing the quality score of the corresponding segment. **Claim 15**: The method (600) according to claim 13, further comprising generating, for display, a simulation model (400) of the shaped part at the candidate position, the simulation model including a graphic indicator (402) corresponding to each of the segments, the graphic indicator representing the quality score of the corresponding segment. **Claim 16** Determining one or more preferred positions of the shaped part (302) relative to the platform (102) and further comprising the step of improving the quality of the shaped part regarding additive manufacturing of the shaped part at the candidate position (304), the method (600) according to any one of claims 13 to 15.

17. The method (600) according to claim 16, further comprising the step of controlling the additive manufacturing equipment (101) to additively manufacture the shaped part (302) at one of the one or more preferred positions on the platform (102).

18. A segment of the shaped part (302) with a small incident angle has a higher quality score than the shaped part with a large incident angle, the method (600) according to any one of claims 13 to 17.

19. The method (600) according to any one of claims 13 to 18, further comprising the step of aggregating the quality scores of the segments to calculate an overall position score associated with the candidate position (304).

20. The candidate position (304) is a first candidate position, The method is, Determining quality scores of the plurality of different segments (312, 332) of the shaped part (302) at a second candidate position of the shaped part on the platform (102) based on the one or more geometric features of the segments at the second candidate position (452), wherein the shaped part at the second candidate position has at least one of a different location, inclination, or rotational orientation with respect to the shaped part at the candidate position (304), the step of, Aggregating the quality scores of the segments to calculate an overall position score associated with the second candidate position, and Ranking the first and second candidate positions based on the overall position scores of the first and second candidate positions, further comprising. The method (600) according to claim 19.

21. An additive manufacturing system (100), comprising one or more processors (118) configured to determine one or more geometric features of each of a plurality of segments (312, 332) of the build part at candidate positions (304) of the build part relative to the platform (102), wherein the one or more geometric features include an angle of incidence (318) between a beam line (320) extending from an electromagnetic energy source (106) of the additive manufacturing apparatus (101) and a surface normal (319) of a respective skin (310) of the segment (312, 332) proximate to the beam line, and the electromagnetic energy source is configured to emit electromagnetic energy beams in various directions along a plurality of beam lines at a single location of the electromagnetic energy source relative to the additive manufacturing apparatus and the build part to melt a designated portion of the build part, and the plurality of beam lines are used to determine the angle of incidence of the segment, the one or more processors are configured to determine a respective quality score of the segments at the candidate positions based on the one or more geometric features such that segments of the build part with a smaller angle of incidence have a higher quality score than the build part with a larger angle of incidence, the one or more processors are configured to provide one or more preferred positions of the build part for achieving an improvement in the quality of the build part by comparing the determined quality scores of the segments of the build part at the candidate positions with the determined quality scores of the segments of the build part at other candidate positions (452) and additive manufacturing the build part at one of the one or more preferred positions, an additive manufacturing system (100).

Images